<!doctype html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<canvas id="myCanvas" width="300" height="200"></canvas>
<script type="text/javascript">
var ctx = document.getElementById('myCanvas').getContext('2d');
for (var i=1;i<10;i++){   
	ctx.strokeStyle = 'blue';
	ctx.lineWidth = 10;
	ctx.lineJoin = 'miter';
	ctx.miterLimit = i*10;
	ctx.beginPath();
	ctx.moveTo(10,i*30);
	ctx.lineTo(100,i*30);
	ctx.lineTo(10,33*i);
	ctx.stroke();
}

</script>
</body>
</html>  
